pRnvinpn Core C has both research and service goals, with the overall theme of developing new and useful imaging and dosimetry approaches to help optimize PDT in preclinical models and clinical studies. The systems used by each project vary considerably,yet the file systems, data analysis, planning and dosimetry concepts can be centralized and inter-project communication in this area can significantly enhance the quality of research. The core is subdivided into four distinct aims, including (!) Structural and functional imaging and dosimetry; (ii) Photophysical imaging/monitoring in vivo; (iii) Molecular imaging in vivo; and (iv)Technology translation. These aims all work with the projects to ensure that developments from one project may assist in another, and that methods, doses, image files, and developed softwaregets used to the highest potential. There are specific areas in structural dosimetry which will be developed including optical imaging translation, clinical dosimetry, mesh creation and light modeling tools, and visualization software. The core will assist Projects 1 and 2 in establishing functioning dosimetry system for all clinical trials, complete with instrumentation to measure the light and PS, as well as treatment planning software which has the capabilities to adapt the light doses in real time. The photophysical dosimetry will involve development of a specialized high resolution fluorescence imaging system for skin cancer treatment mapping. The variance of PS concentration will be studied in both skin and pancreatic cancer models, as well as installation and testing of singletoxygen dosimetry in collaboration with PSI. The recent developments in molecular imaging will be extended into imaging in vivo, and be used to quantify the expression EGFR, VEGF levels, and expression of other key proteins in vivo. Integrated optical tomography with MRI, US, CT will be used to study these with high image resolution. The final aim tackles the complex issue of technology transfer, and when to spend time on patenting and shareware distribution of technology. We have partners in several companies, and these will be leveraged to help guide our next steps, as well as working through the technology transfer offices of each institution, and the CIMIT center at MGH to fulfill the NIH Roadmap goals of private public partnerships. The core will administer and update a share ware site for distribution of software tools and dosimetry designs, for systems, which do not have immediate commercial potential, yet would benefit the field of PDT in general by distribution to other academic centers. The core is centered at Dartmouth and MGH, as these sites have been the locus of technology developments in the past funding period, yet the key personnel and collaborators at each site have planned bi-annual meetings and more often weekly meetings planned during clinical trials. Enhanced file transfer and customized software tools will improve the interactions planned and make this core significantly improve the quality of research at each of the project sites. The potential benefits to public health that this Core provides is in the form of new dosimetry and imaging tools for better treatment outcomes and initiating commercialization of research in the Program in partnership with industry.